Urinary tract infections in the early posttransplant period after kidney transplantation: etiologic agents and their susceptibility

Objective

Urinary tract infection (UTI) is among the most common infections in solid organ transplantation, especially in kidney transplantation.

Patients and Methods

This study included 295 adult patients undergoing KTx between September 2001 and December 2007. All patients were followed prospectively for UTI during the first 4 weeks after surgery. Samples of urine were investigated by bacteriological cultures to identify microorganisms in accord with standard procedures. Susceptibility testing was performed using Clinical and Laboratory Standards Institute procedures.

Results

Urine specimens (n = 582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n = 291), the most common were Gram-negative bacteria (56.4%) predominantly Serratia marcescens (32.3%) and Enterobacter cloacae (14.6%). Extended- spectrum beta-lactamase (ESBL+) strains were isolated in 52.5% of cases. Gram-positive bacteria comprised 35.7%; most commonly, high-level aminoglycoside resistant (HLAR; 87.8%) and vancomycin-resistant (VRE; 11%) Enterococci. There were fungal strains in 23 cases (7.9%).

Conclusion

Our study showed predominantly Gram-negative rods from the Enterobacteriaceae family comprising (84.8%) of Gram-negative isolates: 52.5% ESBL and resistant enterococci (87.5%) in Gram-positive isolates. The increased proportion of isolates of multi-drug-resistant bacterial agents which can cause severe UTIs may be due to our frequent use of ceftriaxone for perioperative bacterial prophylaxis.     

Long-term outcomes of kidney transplants with multiple renal arteries: a retrospective study

Objective

The aim of this study was to investigate whether kidney transplantations performed using grafts with multiple arteries negatively affected renal function or increased the risk of vascular or urologic complications.

Methods

Among 249 kidney transplant patient followed for at least 1 year between 2000 and 2005, we retrospectively evaluated their donor renal artery anatomy to compare postoperative vascular and urologic complications: creatinine clearance at 1, 2, and 5 years, as well as graft survival at 3 and 5 years.

Results

While 214 (85.9%) displayed a single artery (group 1), 35 (14.1%) showed multiple renal arteries (group 2). Thirty-one of the group 2 allografts had two, three donors had three, and one had four arteries. The postoperative vascular and urologic complications and the creatinine clearance values at 1, 2, and 5 years of both groups were similar. The 3- and 5-year graft survivals among group 1 were 95% and 90%, whereas those of group 2 were 94% and 91% respectively (P < .05).

Conclusion

Our study indicated that multiple renal arteries did not adversely affect postoperative urologic or vascular complications or kidney allograft or patient survival compared with single renal artery cases.     

A threat of the Klebsiella pneumoniae carbapenemase-producing strains among transplant recipients

Background

Infections due to Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae are associated with increased therapeutic failure and mortality. Our laboratory recognized several strains producing KPC, most of which originated from transplantation ward patients.

Materials and Methods

All strains of K pneumoniae resistant to at least 1 carbapenem isolated in 2010 were examined for KPC production by disc diffusion and then verified by molecular methods.

Results

All positive strains originated from 7 patients. Six of them were from transplantation wards. None of the KPC-producing strains was isolated from the patient's blood.

Conclusions

A quick, accurate diagnosis of KPC-producing strains enabled immediate isolation of carriers or infected persons. Isolation prevented spread of dangerous strains among immunocompromised patients and reduced the possibility of serious infections.     

Infective Complications Associated With Ureteral Stents in Renal Transplant Recipients

Objective

Stenting of the ureter is commonly performed during renal transplantation to avoid early complications. However, it predisposes to infections that may pose a significant threat to the graft and patient. Our study sought to investigate the incidence of infections associated with stents in renal transplant recipients.

Patients and Methods

A retrospective analysis of 100 consecutive renal transplant recipients performed over 1 year with 6 months follow-up.

Results

The median recipient age was 46 years (range, 19-71 years). Among the study group, 75 patients received an organ from deceased donor and 25 from live donor. In our study, there were 79 patients with a stent (ST) and 18 without a stent (WOST); 3 patients who required nephrectomy were excluded from the study. There were 2 ureteric stenoses that occurred following stent removal: 1 required surgical correction and 1 was treated radiologically. There were no cases of urinary leak. The incidence of urinary tract infection (UTI) was significantly greater among ST compared with WOST subjects (71% vs 39%; P = .02). New episodes of UTI following removal of the stent were more common among patients who had experienced infections while having a stent compared with infection-free stented patients (54% vs 30%; P = .04).

Conclusions

A ureteric stent may help to reduce early postoperative complications (leak and stricture), but increased the likelihood of UTI. Infection while having a ureteric stent was associated with a high recurrence rate of UTI even after stent removal.     

Risk Factors for Urinary Tract Infections During the First Year After Kidney Transplantation

Introduction

Urinary tract infections (UTI) have been reported to occur with frequencies ranging from 30% to 60% in kidney transplant recipients during the first year posttransplantation. UTI is the main cause of infectious complications in this period. The objective of this study was to evaluate the incidence of UTI, during the first year posttransplantation and to identify the risk factors associated with its development, as well as its impact on graft function.

Patients and Methods

This retrospective cohort study had as a primary outcome the development of UTI, defined as the presence of more than 100,000 colony-forming units (CFU) of a pathogenic organism by mL of urine. The univariate analysis was performed with chi-square test for categorical variables and Student t test for continuous ones metrics. We performed multivariate analysis with logistic regression. P < .05 was considered statistically significant.

Results

We studied 176 kidney transplant recipients, including 54.5% of male gender and with an overall average age of 37 ± 12 years. The UTI incidence was of 35.8% (n = 63). The bacterium most frequently found in urine cultures was Escherichia coli (n = 46). In this study, the risk factors that were independently associated with UTI development were age, female gender, days of bladder catheterization, genitourinary anatomic alterations, and UTI during 1 month prior to kidney transplantation.

Conclusion

This type of study makes it possible to identify risk factors and to formulate strategies focused on particular risk factors.     

Participation of strictly anerobic bacteria in infections among hospitalized transplant patients in a clinical hospital in Warsaw

Background

Many strictly anerobic bacteria are a part of the human commensal microflora. Especially multitudinously they inhabit the skin, mucous membranes, gastrointestinal tract, respiratory, and genital tracts. Infections with these bacteria may occur after escape of the bacteria from their natural habitat. There are often mixed anerobic and aerobic infections. After rupture of the gastrointestinal tract or surgery, the organisms can cause significant pathology including abscesses and bacteremia.

Objective

The aim of this study was to estimate the prevalence of gram-negative strictly anerobic bacteria isolated from different samples collected from patients on transplant wards.

Materials and Methods

Samples from patients with suspected infections. Underwent isolation and identification of microorganisms under anerobic conditions using standard laboratory methods.

Results

Gram-negative rods were observed in 46% of clinical samples, most frequently Bacteroides genus as well as Fusobacterium necrophorum/F.nucleatum and F.mortiferum (14%). Most species of the genus Bacteroides were accompanied by Escherichia coli, less frequently with other aerobic gram-negative rods or gram-positive cocci.

Conclusion

Gram-negative bacteria were frequently isolated in the samples. Because they are the part of the normal flora, this observation indicated the endogenous nature of infections resulting from bacterial translocation out of their natural habitat.     

Urinary Tract Infections in the Early Posttransplant Period After Simultaneous Pancreas–Kidney Transplantation

Objective

Urinary tract infection (UTI) is among the common infection in simultaneous pancreas-kidney transplantation (SPKT).

Patients and Methods

The study included 26 adult patients undergoing SPKT between September 2001 and December 2006. All the patients were followed prospectively for UTI during the first 4 weeks after surgery. Urine samples were investigated for bacteriologic cultures. The micro-organisms were identified in accordance with standard bacteriologic procedures. Susceptibility testing was carried out using Clinical and Laboratory Standards Institute (CLSI) procedures.

Results

Among 77 urine specimens obtained from all recipients during the first month, there were 30 isolated bacterial strains. The most common were Gram-positive bacteria (53.3%) with predominance of enterococci (75%) associated with high levels of aminoglycoside resistant strains (HLAR; 58.3%) and vancomycin-resistant strains (VRE; 25%). Gram-negative bacteria were detected in 46.7% of positive cultures.

Conclusions

In our study, enterococci predominated as 75% of Gram-positive isolates. The increased proportion of multi-drug-resistant bacteria, which can caused severe UTI in patients after SPKT, may be due to the frequent use of prophylaxis of bacterial infections in patients.     

Is removal of the stent at the end of 2 weeks helpful to reduce infectious or urologic complications after renal transplantation?

Objective

Ureteral stents are used to reduce urologic complications after renal transplantation. However, they predispose to infection. The optimal time to keep them in the urinary tract has not yet been defined. The aim of this study was to evaluate the effect of early removal at the end of 2 weeks on urinary tract infections and early urologic complications (within 3 months), such as ureteroneocyctostomy leakage as well as ureteral anastomosis stricture or obstruction.

Methods

We retrospectively analyzed the medical records of 48 patients who underwent renal transplantation using a ureteral stent. The patients were divided into two groups according to the time of stent removal: at the end of 2 weeks (group A; n = 10) versus at a later time (group B; n = 38).

Results

The urologic complication rate was 0% in group A and the urinary tract infection rate, 2%. The urologic complication rate was 0% in group B and the urinary tract infection rate, 35%.

Conclusion

Early removal of the stent at the end of 2 weeks after renal transplantation is decreased the rate of urinary tract infections.     

Impact of early ureteric stent removal and cost-benefit analysis in kidney transplant recipients: results of a randomized controlled study

Introduction

Duration of retaining ureteric stent in kidney transplantation is still controversial. Our study aimed to compare healthcare expenditures in kidney transplant recipients with early or routine ureteric stent removal.

Methods

This study was a post hoc analysis of data from a single-center parallel randomized controlled open-label study. Ninety patients who underwent kidney transplantation at a university-based hospital in Thailand from April 2010 to January 2011 were enrolled. Patients were randomized to early ureteric stent removal (8 days) or routine ureteric stent removal (15 days) after kidney transplantation. The costs of direct health care associated with kidney transplantation, urologic complication, and urinary tract infection (UTI) within the postoperative period among the 2 groups were compared.

Results

Seventy-four patients (58% living donor) fulfilled the randomized criteria (early removal, n = 37; routine removal, n = 37). By intention-to-treat analysis, incidence of UTI in early stent removal was less than the routine stent removal group (15/37, 40.5% vs 27/37, 72.9%; P = .004). Urologic complication showed no significant difference between the early and routine groups (4/37 vs 2/37; P = .39). The cost-benefit analysis of early over routine stent removal was 2390 United States dollars (USD) per patient (11,182 vs 8792 USD). Presence of UTI significantly increase the hospitalization cost of 5131 USD per patient (mean cost = 12,209 vs 7078 USD; P < .001).

Conclusion

UTI in the early post-kidney transplantation period increases healthcare cost. Early ureteric stent removal can reduce UTI and reduce hospitalization cost. This approach shows cost-benefit in the early management of kidney transplant recipients.     

Evaluation of Epstein-Barr virus load in saliva before and after renal transplantation

Introduction

Posttransplant lymphoproliferative disorders (PTLD) arising in solid organ transplant patients show a strong correlation with Epstein-Barr virus (EBV) infection. The aim of our study was to evaluate the frequency of EBV DNA levels before and after transplantation among saliva samples of Iranian kidney transplant patients.

Materials and Methods

In 40 kidney transplant recipients and their healthy donors, we evaluated the EBV DNA levels in saliva samples by quantitative polymerase chain reaction method using samples obtained 1 hour before transplantation surgery. In addition, 3 months after transplantation we evaluated EBV DNA levels in recipients for comparison with preoperative levels. Exclusion criteria included hepatitis B, hepatitis C, and human T-cell leukemia virus infections before transplantation as well as HIV-positive patients under highly active antiretroviral therapy, graft rejection requiring dialysis and active viral infection of oral cavity.

Results

Before renal transplantation, there was no significant difference in saliva EBV DNA levels between kidney donor and recipient patients (P = .8). The levels increased significantly to 67.6% in the recipient group after transplantation (P = .01).

Conclusion

We observed that EBV was more frequently present in the oral mucosa after renal transplantation. Thus, we can follow these patients for EBV infection using saliva examinations as a simple screening method.     

The role of obesity in kidney transplantation outcome

Background

The number of obese kidney transplant candidates has been growing. However, there are conflicting results regarding to the effect of obesity on kidney transplantation outcome. The aim of this study was to investigate the association between the body mass index (BMI) and graft survival by using continuous versus categoric BMI values as an independent risk factor in renal transplantation.

Methods

We retrospectively reviewed 376 kidney transplant recipients to evaluate graft and patient survivals between normal-weight, overweight, and obese patients at the time of transplantation, considering BMI as a categoric variable.

Results

Obese patients were more likely to be male and older than normal-weight recipients (P = .021; P = .002; respectively). Graft loss was significantly higher among obese compared with nonobese recipients. Obese patients displayed significantly lower survival compared with nonobese subjects at 1 year (76.9% vs 35.3%; P = .024) and 3 years (46.2% vs 11.8%; P = .035).

Conclusions

Obesity may represent an independent risk factor for graft loss and patient death. Careful patient selection with pretransplantation weight reduction is mandatory to reduce the rate of early posttransplantation complications and to improve long-term outcomes.     

The clinical significance of human leukocyte antigen antibody development in kidney transplantation

Background

This retrospective study uses the LAT-M (One Lambda Inc., Calif) screen assay to reexamine the impacts (a), of pretransplant human leukocyte antigen (HLA) antibody on long-term graft survival; (b) posttransplant HLA antibody on long-term graft survival and (c) immunosuppressive regimen on posttransplant HLA antibody development.

Patients and methods

Pretransplant sera from 222 renal transplant recipients and posttransplant sera from 216 renal transplant recipients were studied for the impact of HLA antibody on long-term graft survival.

Results

Among the patients who did not display pretransplant HLA antibodies, 85% enjoyed 5-year and 59% 10-year graft survival, whereas the patients who tested positive were 83% and 83% (P = .5596). Among the patients who did not show posttransplant HLA antibodies, 99% enjoyed 5-, 91% 10-, and 65% 15-year graft survival, whereas for the 44 patients who tested positive they were 59%, 44%, and 30%, respectively (P < .0001). Patients prescribed cyclosporine + myfortic (odds ratio 0.17, P = .05) or FK + Cellcept (odds ratio 0.36, P = .04) showed the lowest posttransplant HLA antibody development.

Conclusion

Both regimens improve graft survival.     

Lack of cytomegalovirus and polyomavirus coexistence in Iranian kidney transplant recipients

Introduction

Maintenance of kidney graft function is essential, averting infection and coinfection. Cytomegalovirus (CMV) and BK polyomavirus (BKV) coinfection have been reported. There are a few studies of CMV and BKV infection in kidney transplant recipients in Iran, but no studies of their coinfection.

Objective

To assess the coexistence of CMV and BKV infection in renal transplant recipients.

Patients and Methods

The presence of CMV and BKV was assessed using real-time polymerase chain reaction in a cross-sectional study in 91 renal transplant recipients at 1 month posttransplantation. Assessment of CMV was performed only in blood samples, whereas BKV was assessed in both serum and urine samples.

Results

The 91 patients included 57 men (62.6%) and 34 women (37.4%), who ranged in age from 19 to 76 years. Simultaneous evaluation of CMV in plasma and BKV in urine demonstrated no significant association. Of 24 patients positive for BKV in urine, 8 (33.3%) were positive for CMV in plasma. Sixty-seven patients tested negative for BKV in urine, whereas 23 (34.4%) tested positive for CMV, which is unremarkable. Comparison of coinfection with plasma CMV and plasma BKV demonstrated no significant correlation. In 3 patients positive for BKV in plasma only, 1 (33.3%) was positive for CMV, whereas in 88 patients negative for BKV in plasma, 30 were positive for CMV.

Conclusion

No significant association was observed between CMV and BKV infections in kidney transplant recipients.     

Urologic complications in kidney transplantation: a single-center experience

Introduction

Urologic complications are an important cause of morbidity in kidney transplantation. To prevent this occurrence, several studies have reported the benefit of stenting. The aim of this study was to compare the efficacy of two different types of stents to protect the urinary anastomosis in kidney transplantation.

Methods

We performed a retrospective analysis of 139 kidney transplant recipients who underwent ureteralneocystostomy by the Lich-Gregoire technique between January 1995 and July 2010. On the basis of the type of stent we divided transplant patients into two groups: group A (n = 90), the internal-external Bracci catheter and group B (n = 49), the double-J stent. The urologic complications evaluated in both groups were: urinary tract leakage, obstruction, and infections. We also recorded the duration of the postoperative hospitalization.

Results

The incidences of urinary fistulae and ureteral strictures between the two groups were similar (around 3%). A higher incidence of urinary infections, however, was registered among group A compared with group B (46% vs 10%; P < .05). The postoperative hospitalization period was consequently longer in group A then group B (35 ± 3 vs 24 ± 2 days; P < .05).

Conclusion

In our series of kidney transplantations, the occurrence of urinary fistulae and ureteral strictures was not influenced by the type of stent. The use of a double-J stent, however, appeared to be associated with a significantly decreased incidence of urinary tract infections leading to shorter postoperative hospitalizations.     

A correlation between polyomavirus JC virus quantification and genotypes in renal transplantation

Objective

To determine whether the John Cunningham virus (JCV) viral load and the multigenotypes in viruria are correlated with transplant patients.

Methods

The urine of 60 renal transplant patients and 60 healthy controls were screened. We used quantitative real-time polymerase chain reaction and capillary electrophoresis to assess viral load and genotype respectively.

Results

The incidence of viruria and viral load were higher in transplant patients with P = .0092 and P = .0094, respectively. The incidence of different genotype in transplant patients versus controls was 8.3% versus 13.3% for single genotype, 26.7% versus 5% for 2 genotypes, and 5% versus 0% for multigenotypes (P = .0004). The incidence of more than 2 genotypes was high in people with a high viral load and closely related with the transplant patients (P = .007).

Conclusions

Not only viral load but also genotypes are important as a screening parameter to understand the immune milieu of the patients to prevent subsequent complications like polyomavirus nephropathy, infection, and malignancy.     

Urinary tract infections in renal transplant recipients

Introduction

Urinary tract infections (UTIs) are most common infections in renal transplant recipients and are considered a potential risk factor for poorer graft outcomes.

Aim

To evaluate incidence, clinical manifestations, microbiology, risk factors for UTIs, and the influence of UTIs on long-term renal graft function.

Patients and methods

We analyzed urine cultures with reference to clinical data of patients who received a renal transplantation from January to December 2009 with a 12-month follow-up.

Results

The 1170 urine cultures were correlated with clinical data from 89 renal transplant recipients, including 58.4% males and on overall mean age of 48 ± 14 years. The 151 episodes in 49 patients consisted of asymptomatic bacteriuria (65%, n = 98); lower UTIs (13%, n = 19); and upper UTIs (22%, n = 34), as well as five cases of bacteremia. Nearly 48% of UTIs were diagnosed during the first month posttransplantation. The most frequently isolated uropathogens were Enterococcus faecium (33%, n = 24) and Escherichia coli (31%, n = 23). Beginning from the second month, most frequently found bacterium in urine cultures was E coli (65% n = 51). Risk factors for posttransplant UTIs were female gender and a history of an acute rejection episode and/or a cytomegalovirus (CMV) infection. All patients with vesicoureteral reflux of strictures at the ureterovesical junction suffered recurrent UTIs (n = 7). The evolution of renal graft function did not differ significantly between patients with versus without UTIs.

Conclusions

UTIs a frequent problem after kidney transplantation most commonly exist as asymptomatic bacteriuria. E coli and E faecium are ther predominant pathogens. Exposure to intensified immunosuppression due to acute rejection episodes or CMV infections represents a risk factor for UTIs. Vesicoureteral reflux or strictures at the ureterovesical junction are risk factors for recurrent UTIs. UTIs did not impair 1-year graft function.     

Urinary Tract Infections in Renal Transplant Recipients: Virulence Traits of Uropathogenic Escherichia coli

Background

Urinary tract infection (UTI) is the most common infectious complication after renal transplantation. Most infections are caused by uropathogenic Escherichia coli (UPEC). There are limited data on the prevalence of virulence traits among UPEC isolated from renal transplant recipients. This study compared the phenotypic and genotypic profiles of UPEC strains isolated from recipients with those from control patients.

Methods

E coli isolates that caused UTI in recipients versus nonimmunosuppressed control patients were characterized according to phylogenetic group and the presence of urovirulence genes pap1/pap2; sfa1/sfa2; afa1/afa2; aer1/aer2; and cnf1/cnf2.

Results

Thirty-six UPEC isolates from recipients and another 27 from control individuals were included in the study. The proportion of episodes of pyelonephritis in recipients (50%) versus control subjects (41%) was similar (P = .46). However, secondary bacteremia was observed only among recipients (n = 8; P < .001). There was no significant difference in the distribution of phylogenetic groups or the prevalence of analyzed virulence traits between UPEC isolated from the 2 groups. Nevertheless, strains associated with secondary bacteremia in recipients showed a higher prevalence of mannose-resistant hemagglutination (P = .013).

Conclusion

The phenotypic and genotypic characteristics of UPEC isolated from recipients were similar to those from control patients at a tertiary care center. Secondary bacteremia in recipients was associated with a higher prevalence of mannose-resistant hemagglutination.     

Effect of systemic corticosteroids on elective left-sided colorectal resection with colorectal anastomosis

Background

The impact of systemic steroid therapy on surgical outcome after elective left-sided colorectal resection with rectal anastomosis is not well known.

Methods

We compared 606 consecutive patients including 53 patients who were on steroids and undergoing surgery between 1995 and 2005.

Results

Postoperative mortality and anastomotic leakage rates were equivalent. The postoperative complications rate, especially infections, was higher in steroid-treated patients than in non-steroid-treated patients: 38% (20 of 53 patients) versus 25% (139 of 553 patients), respectively (P = .046). In the steroid group, univariate analysis revealed 3 significant risk factors for postoperative complications: blood transfusion, preoperative anticoagulation, and chronic respiratory failure. In a multivariate analysis, blood transfusion and chronic respiratory failure remained independent factors for postoperative complications.

Conclusion

Patients on steroids have a higher incidence of postoperative complications after elective left-sided colorectal resection with rectal anastomosis.